TIAN Wen1,2, WANG Yong-shi3, MA Li-chi2, XIN Ye1,2, ZHANG Shun1,2, ZHANG Ming-hua2, XU Hao-qing2
(1. Postdoctoral Scientific Research Workstation of Shengli Oilfield Company, Dongying 257000, China;
2. Exploration and Development Research Institute, Shengli Oilfield Company, Sinopec, Dongying 257022, China;
3. Shengli Oilfield Company, Sinopec, Dongying 257000, China)
Abstract: Combined the characteristics of detrital zircon mineral, cathodoluminescence image and characteristics of the age spectrum distribution, provenance of sandstone in the Upper Shihezi Formation, the Permian system from Linyou area in the southwestern margin of the Ordos Basin were analyzed by LA-ICP-MS U-Pb dating method. Results show that the detrital zircon U-Pb age distribution mainly has three groups peak age, 1864 Ma, 2500 Ma, 441 Ma, and also has an ancient subprime detrital zircon age of 3.3 Ga and a younger age group from 299 to 363 Ma. The two groups peak age of zircon grains accounted for 82.2% of the total, indicating that late Permian stone box on the stage of the North China Craton provides the main source for the southwest margin of the Ordos Basin. The presence of 3.3 Ga age also indicates that it comes from the North China Craton. The 441Ma peak zircon grains account for 10.4% of the total, indicating that it may come from the Qinling－Qilian orogenic belt, due to the lack of the Neoproterozoic age of 800－1000 Ma, showing that the uplift and denudation extent of Qinling－Qilian orogenic belt on the Upper Shihezi stage is low. The age group 299－363 Ma indicates that it probably comes from the Xing－Meng orogenic belt magmatic arc in the northern margin of the North China Craton.
Keywords: detrital zircon; U-Pb age; provenance analysis; North China Craton; Ordos Basin
